Nitrogen-Enriched Reduced Graphene Oxide for High Performance Supercapacitor Electrode.

Abstract

Nitrogen-enriched reduced graphene oxide electrode material can be successfully prepared through a simple hydrothermal method. The morphology and microstructure of ready to use electrode material is measured by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). Physical characterizations revealed that nitrogen-enriched reduced graphene oxide electrode material possessed high specific surface area of 429.6 m² · g-1, resulting in high utilization of electrode materials with electrolyte. Electrochemical performance of nitrogen-enriched reduced graphene oxide electrode was also investigated by cyclic voltammetry (CV), galvanostatic charge/discharge measurements and electrochemical impedance spectroscopy (EIS) in aqueous in 6 M KOH with a three-electrode system, which displayed a high specific capacitance about 223.5 F · g-1 at 1 mV · s-1. More importantly, nitrogenenriched reduced graphene oxide electrode exhibited outstanding stability with 100% coulombic efficiency and with no specific capacitance loss under 2 A · g-1 after 10000 cycles. The supercapacitive behaviors indicated that nitrogen-enriched reduced graphene oxide can be a used as a promising electrode for high-performance super-capacitors.